Intra-articular joint replacement

ABSTRACT

A method of forming a shoulder prosthesis includes resecting an end portion of a humerus to form a resected end of the humerus and a resected portion separated from the humerus, the resected portion having an outer convex surface and an inner surface. The inner surface of the resected portion is processed to include a concave articular surface. The outer convex surface of the resected portion is implanted in the resected end of the humerus. An implant having a convex articular surface is secured to a glenoid. The concave articular surface of the resected portion is articulated with the convex articular surface of the implant.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/069,158, entitled Intra-Articular Joint Replacement, filedOct. 31, 2013, which is a continuation of U.S. patent application Ser.No. 12/787,124, entitled Intra-Articular Joint Replacement, filed May25, 2010, which is a continuation of U.S. patent application Ser. No.12/337,385, entitled Intra-Articular Joint Replacement, filed Dec. 17,2008, which is a continuation-in-part of U.S. patent application Ser.No. 12/020,913, entitled Method and Apparatus for Fitting a ShoulderProsthesis, filed Jan. 28, 2008, which claims priority to Frenchapplication No. 0700622, entitled “Méthode et ensemble d'instrumentationchirurgicale pour poser une prothèse totale d'épaule inversée, etprothèse correspondante,” filed Jan. 30, 2007, and also claims thebenefit of U.S. Provisional Application Ser. Nos. 60/888,437 filed Feb.6, 2007 and 60/971,762 filed Sep. 12, 2007, both entitled “Method andApparatus for Fitting an Inverted Shoulder Prosthesis,” and U.S.Provisional Application Ser. No. 61/015,042, entitled “Intra-ArticularJoint Replacement,” filed Dec. 19, 2007, the complete disclosures ofwhich are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a method and apparatus for implanting aprosthesis at the intersection of two or more bone, and in particular,to a method and apparatus for processing and implanting a resectedportion of a humerus to act as an articular surface for aninterpositional implant of a shoulder prosthesis.

BACKGROUND OF THE INVENTION

In the field of total shoulder prostheses, prostheses are commonly saidto be inverted when they comprise a glenoid component that is integralwith the glenoid surface of a scapula of a patient's shoulder and thatdelimits a convex articular surface and a humeral component that isintegral with the humerus of the patient's shoulder and that delimits aconcave articular surface. The cooperation of the articular surfaces ofthe glenoid and humeral components allow an articulated connection to bereproduced at the shoulder. However, it is common with this type ofprosthesis that during adductive movement of the shoulder, the lowerportion of the humeral prosthetic component strikes the pillar of thescapula, i.e. the lower portion of the glenoid located just below theglenoid prosthetic component (when the patient is standing upright).This interference between the humeral prosthetic component and thescapula limits the range of adductive movement of the shoulder and maycause pain to the patient or even lead to the prosthesis becomingdislodged due to, for example, osteolysis of the scapula.

Another method used to replace damaged shoulder joints isinterpositional arthroplasty. The method of interpositional arthroplastyuses tissue from the patient or an artificial replacement to repair adamaged or malformed joint. An interpositional implant is positioned atthe joint to act as an engagement surface between two adjacent bonestructures to allow articular movement. In the particular field ofinterpositional shoulder arthroplasty, the humeral metaphysis istypically impacted to form an engagement surface for an interpositionalimplant positioned between a glenoid component (or glenoid) and ahumeral component (or humeral metaphysis). However, if the cancellousbone in the humeral metaphysis is of poor or degraded quality, thecancellous bone may lead to gradual subsidence of the interpositionalimplant within the humeral metaphysis. It is thus desirable to developan interpositional implant with a metaphyseal articular surface thatwill provide support and protection to the metaphyseal cancellous bone.

SUMMARY OF THE INVENTION

Some embodiments relate to a method of forming a shoulder prosthesis,including forming a concave articular surface into an end portion of ahumerus, including compacting bone of the end portion to define theconcave articular surface. An implant having a convex articular surfaceis secured to a glenoid. The concave articular surface of the humerus isarticulated with the convex articular surface of the implant.

Other embodiments relate to a method of forming a shoulder prosthesis,including resecting an end portion of a humerus to form a resected endof the humerus and a resected portion separated from the humerus, theresected portion having an outer convex surface and an inner surface.The inner surface of the resected portion is processed to comprise aconcave articular surface. The outer convex surface of the resectedportion is implanted in the resected end of the humerus. An implanthaving a convex articular surface is secured to a glenoid. The concavearticular surface of the resected portion is articulated with the convexarticular surface of the implant.

Still other embodiments relate to a method of forming a shoulderprosthesis, including forming a recess in an end portion of a humerusand disposing a reinforcing structure across at least a portion of therecess to form a concave articular surface of the humerus. Thereinforcing structure is attached to the humerus. An implant having aconvex articular surface is secured to a glenoid. The concave articularsurface of the resected portion is articulated directly with the convexarticular surface of the implant.

While multiple embodiments are disclosed, still other embodiments of thepresent invention will become apparent to those skilled in the art fromthe following detailed description, which shows and describesillustrative embodiments of the invention. Accordingly, the drawings anddetailed description are to be regarded as illustrative in nature andnot restrictive.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1A is a schematic view of an intra-articular prosthesis implantedin a patient's shoulder in accordance with an embodiment of the presentinvention.

FIG. 1B is a schematic view of an alternate prosthesis implanted in apatient's shoulder in accordance with an embodiment of the presentinvention.

FIG. 2 is a schematic view of a cutting guide for a proximal portion ofa humerus in accordance with an embodiment of the present invention.

FIG. 3 is a schematic view of a resected portion of the proximal portionof the humerus in accordance with an embodiment of the presentinvention.

FIG. 4 is a schematic view of a method of preparing a resected proximalportion of the humerus in accordance with an embodiment of the presentinvention.

FIG. 5 is a schematic view of a method and apparatus for implanting theresected portion of the proximal portion of the humerus in accordancewith an embodiment of the present invention.

FIG. 6 is a schematic view of a resected portion implanted into aproximal portion of the humerus in accordance with an embodiment of thepresent invention.

FIG. 7 is a schematic view of a resected portion implanted into aproximal portion of the humerus using fasteners in accordance with analternate embodiment of the present invention.

FIG. 8 is a schematic view of a resected portion implanted into aproximal portion of the humerus using sutures in accordance with analternate embodiment of the present invention.

FIG. 9 is a schematic view of an interpositional implant engaged with animplanted resected portion in accordance with the present invention.

FIG. 10 is a schematic view of intra-articular prostheses implanted in apatient's hand in accordance with an embodiment of the presentinvention.

FIG. 11 is a schematic view of intra-articular prostheses implanted in apatient's foot in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A shows a schematic view of a prosthesis 10 including a glenoidcomponent 12, a humeral component 14 and an interpositional implant 16.The glenoid component 12 is implanted in the scapula S of the glenoid G.The method and apparatus of the various embodiments of the presentinvention disclosed herein may be used with a variety of glenoidcomponents, such as for example those disclosed in U.S. Pat. Nos.7,033,396; 6,953,478; 6,761,740; 6,626,946; 5,702,447 and U.S.Publication Nos. 2004/0220673; 2005/0278030; 2005/0278031; 2005/0278032;2006/0020344, which are hereby incorporated by reference. Although theprosthesis 10 is primarily discussed as being implanted in a patient'sshoulder, the prosthesis 10 may also be modified and implanted in otherlocations of a patient's body without departing from the intended scopeof the present invention. For example, the prosthesis 10 may be modifiedto be implanted in a patient's hip, ankle, hands, or feet.

In the illustrated embodiment, the glenoid component 12 includes anarticular member 18 with a generally concave articular surface 20 thatengages the interpositional implant 16. Given that the articular member18 is positioned immediately adjacent the glenoid G, the interpositionalimplant 16 is remote from the resected surface of the glenoid G in thesense that, if the articular member 18 were omitted, the interpositionalimplant 16 would be directly juxtaposed with the glenoid G. Thus, onaccount of the articular member 18, the interpositional implant 16 andthe humeral component 14 are laterally remote from the glenoid G,limiting the risk of the humerus H interfering with the bottom of theglenoid G, i.e. with the pillar P of the scapula S. Alternatively, anarticular member 18 may not be required within the glenoid G. In thiscase, the interpositional implant 16 would articulate directly with theglenoid G.

The humeral component 14 includes an articular member 24 formed from aresected portion 30 (shown in FIG. 3) of the proximal humerus PH that isremoved during processing of the humerus H. The proximal humerus PH ispreferably resected such that the resected portion 30 is preferably asingle, unitary piece. In this form, an outer convex surface 58 of theresected portion 30 is implanted into the proximal humerus PH as asingle unit, rather than as fragments.

Alternatively, the resected portion 30 can be formed from a single pieceor a plurality of pieces taken from the proximal humerus PH or otherlocations in the patient's body. Implantation of the resected portion 30can be supplemented with bone graft material, such as for example apurée of bone substance, bone replacements, bone fillers, bone cementsand/or bone adhesives, or a combination thereof. The bone graft materialcan be formed from the patient's bone, an allograft, a xenograft, or acombination thereof. Various bone replacements, bone fillers, bonecements and bone adhesives are disclosed in U.S. Pat. No. 6,692,563(Zimmerman), which is hereby incorporated by reference. Variousadditives can also be included with the resected portion, including, butnot limited to bone growth agents and pain inhibitors.

As will be discussed further below, the resected portion 30 is preparedand impacted into the proximal humerus PH to form the articular member24 having a concave articular surface 32. The preparation of theresected portion 30 can be performed ex vivo or in situ.

In the illustrated embodiment, the humeral component 14 includes anoptional stem 22 located in the medullary cavity M of the humerus H. Theproximal end 28 of the stem 22 supports the resected portion 30 andoptionally serves as an attachment member. For example, a fastener 26can optionally extend through the resected portion 30 and engage thestem 22. It will be appreciated that the stem 22 may be omitted entirelywithout departing from the intended scope of the present invention.

The interpositional implant 16 is positioned between the articularmember 18 of the glenoid component 12 and the articular member 24 of thehumeral component 14. The radius of the interpositional implant 16 istypically equal to or less than the radii of the concave surfaces 20 and32 of the articular member 18 of the glenoid component 12 and thearticular member 24 of the humeral component 14, respectively. When theinterpositional implant 16 is positioned between the glenoid component12 and the humeral component 14, as shown in FIG. 1A, the concavesurfaces 20 and 32 are in mutual surface contact with theinterpositional implant 16, allowing articular movements of thepatient's shoulder.

In an alternate embodiment illustrated in FIG. 1B, the interpositionalimplant 16 is eliminated and a glenoid component 18 with a convexarticular surface 19 is substituted. The articular member 24, created asoutlines in FIG. 1A, engages directly with the convex articular surface19.

FIGS. 2-9 illustrate various embodiments for processing and implantingthe prosthesis 10 into the humerus H. It is to be understood that themethod of implanting the prosthesis 10 described hereinafter is merely anon-limiting illustrative example of a method and instruments used toimplant the prosthesis 10. In other words, the method and theinstruments specified hereinafter can be used to implant prostheses of abroad range of structures, of which, for example, the glenoid and/orhumeral components 12, 14 consist of a plurality of metallic, plasticand/or ceramic-type parts joined together. As previously mentioned, theinterpositional implant 16 may also articulate directly with the glenoidG such that the glenoid component 12 is not included as part of theprosthesis 10.

FIG. 2 is a schematic view of a cutting guide 34 positioned over theproximal humerus PH. In order to prepare the proximal humerus PH forresection, the soft parts (i.e. cartilage) of the proximal humerus PHmay optionally be removed using a deltopectoral or supero-externalapproach.

The cutting guide 34 includes a bell-shaped body 36 secured to a shaft38. An interior surface of the body 36 has a concave surface from whichthe main center of curvature pertains substantially to an axis 40 fromwhich the shaft 38 extends from the body 36. The body 36 is designed tocover the upper portion of the proximal humerus PH in the manner of acap and is perforated to give the surgeon a better view of the proximalhumerus PH when positioning the body 36. The body 36 is thus shaped toreproduce approximately the surface features of the upper proximalhumerus PH of a normal anatomical humerus H. However, in practice, therewill be a range of a plurality of homothetic guiding instruments 34having bodies 36 which have respective dimensions associated with thesize and the state of the patient's bones.

The shaft 38 of the cutting guide 34 is optionally provided with aprotruding tube 42 centered on the axis 40 and the main center ofcurvature of the body 36. Once the body 36 is properly positioned overthe proximal humerus PH, a guide pin 44 having a pointed distal end isintroduced into the protruding tube 42 and inserted into the proximalhumerus PH. The guide pin 44 preferably terminates before the cuttingplane C-C′. The surgeon uses the distal surface 27 on the body 36located in the cutting plane C-C′ to resect the portion 30 from theproximal humerus PH. Alternatively, the surgeon can cut free-handwithout a template.

FIG. 3 shows a schematic view of the resected portion 30 of the proximalhumerus PH. After the proximal humerus PH has been resected, theproximal humerus PH has a cut surface 66 where the resected portion 30was removed. The resected portion 30 includes a convex outer surface 58and an inner cut surface 50 of cancellous bone 52. In one embodiment,the resected portion 30 is prepared ex vivo by impacting the inner cutsurface 50 to compress the cancellous bone 52 to form the generallyinner convex surface 32. As a result, the inner convex surface 32 is alayer of compacted cancellous bone 52 pressed against the inner surface54 of the cortical bone 56.

In another embodiment, the resected portion 30 is prepared ex vivo byremoving the cancellous bone 52 from the cortical bone 56. As a result,the inner convex surface 32 is essentially the inner surface 54 of thecortical bone 56. Either of these procedures can also be performed insitu. That is, after the resected portion 30 is engaged with theproximal humerus PH.

In some embodiments, the cut surface 66 of the proximal humerus PH isprepared to receive the resected portion 30. A hemispherical reaminginstrument 64, shown in FIG. 4, is used to form a concave surface 60 inthe proximal humerus PH. The reaming instrument 64 includes a convexbody 68 having a plurality of teeth 70 to shape the cut surface 66 intothe desired form. The concave surface 60 is preferably the same shape asthe outer convex surface 58 of the resected portion 30.

In another embodiment, the cut surface 66 (shown in dashed lines) iscompacted or carved to form the concave surface 60 on the proximalhumerus PH. Preparing the cut surface 66 of the proximal humerus PH maybe performed using a variety of other techniques known in the artwithout departing from the intended scope of the present invention.Small holes may optionally be drilled through the concave surface 60 toenhance bone integration remodeling once the resected portion 30 isreversed and implanted in the humerus H.

FIG. 5 shows the resected portion 30 being impacted into engagement withthe concave surface 60 of the proximal humerus PH. The resected portion30 is positioned within the concave surface 60 such that the convexouter surface 58 engages the concave surface 60. An impacting instrument78 is then used to drive the resected portion 30 into the proximalhumerus PH to form the articular member 24 having a semi-spherical shapeat the concave surface 60 of the proximal humerus PH. As the resectedportion 30 is driven into the proximal humerus PH, cancellous bone ateach side of the proximal humerus PH is compressed and forms to theshape of the concave surface 60.

In an alternate embodiment illustrated in FIG. 6, the resected portion30 is compacted directly against the cut surface 66, without the reamingstep shown in FIG. 4. By gradually integrating the resected portion 30into the proximal humerus PH, a strong bony or fibrous-cartilaginousunderlying support structure having the concave surface 60 is created tosupport the articular member 24. In addition, the resected portion 30 isused to isolate the cancellous bone 67 in the humerus H from synovialfluids. The resected portion 30 is preferably driven into the proximalhumerus PH as a single unit such that the resulting articular member 24is an integral piece and is not formed of fragmented pieces. Thearticular member 24 has a shape of a metaphyseal cup formed to cooperatewith a variety of interpositional components, such as, for example, afull sphere, a lens-type free interpositional component, or acombination thereof. In one embodiment, the articular member 24 may havea shape of approximately one-third of a sphere.

FIG. 7 shows a schematic illustration of one embodiment of attaching thearticular member 24 to the concave surface 60 of the proximal humerus PHusing a plurality of pins 80. The heads 82 of the pins 80 are preferablyflush with, or recessed below, the concave inner surface 32. Variousbone anchors, known in the art, may also be used in place of the pins80. The pins 80 may be formed of various materials, including, but notlimited to: metallic components and polymeric components. In particular,the pins 80 may be formed of bioresorbable polymers. The pins 80 areparticularly useful when the resected portion 30 includes a plurality ofpieces 30A, 30B, 30C.

In one embodiment, a suture material 84 is optionally attached to one ormore of the pins 80. The suture material 84 extends through the proximalhumerus PH to the opposite side and is anchored to the cortical bone 86using conventional techniques. The suture material 84 operates as atension member to retain the resected portion 30 to the concave surface60 of the proximal humerus PH.

In an alternate embodiment illustrated in FIG. 8, the resected portion30 is attached to the proximal humerus PH using a plurality ofperipheral sutures 90. The sutures 90 may be formed of variousmaterials, including, but not limited to: metallic components andpolymeric components. In particular, the sutures 90 may be formed ofbioresorbable polymers. The resected portion 30 may be fixed within theproximal humerus PH by any fixation mechanism, or combination offixation mechanisms, known in the art without departing from theintended scope of the present invention.

In one embodiment, a reinforcing structure 92, such as for examplereinforcing fibers, a three-dimensional porous matrix or scaffold, islocated between the concave surface 60 on the proximal humerus PH andthe resected portion 30. In the illustrated embodiment, the reinforcingstructure 92 is attached to the cortical bone 86 of the proximal humerusPH by the sutures 90. In one embodiment, the reinforcing structure 92operates like a sling to limit further penetration of the resectedportion 30 into the proximal humerus PH. In another embodiment, thereinforcing structure 92 promotes in-growth between the proximal humerusPH and the resected portion 30. Examples of such reinforcing structuresinclude a porous matrix, a scaffold, a reticulated bioceramic framework,a structured porous tantalum and a synthetic fiber mesh. Various porousmatrices and scaffoldings are disclosed in U.S. Patent Nos. 4,479,271;6,511,511; 6,605,117; 6,797,006; 6,902,584; and 7,250,550, which arehereby incorporated by reference. Although the reinforcing structure 92is discussed as being used in conjunction with the resected portion 30,the reinforcing structure 92 may alternatively be used in place of theresected portion 30 as an articular surface for engaging theinterpositional implant 16 (shown in FIGS. 1 and 9).

In another embodiment, the reinforcing structure 92 extends beyond thesutures 90. The reinforcing structure 92 may be made of any material,natural and synthetic, suitable for implantation. Preferably thereinforcing structure 92 is flexible to permit conformity with theproximal humerus PH. The reinforcing structure 92 material may alsopermit intraoperative cutting or other shaping of the reinforcingstructure 92 to fit a surgical site. For example the reinforcingstructure 92 may be intraoperatively shapeable by cutting with scissors.The reinforcing structure 92 may include natural tissues includingfibrocartilage, fascia, pericardium, and/or other natural tissues. Thereinforcing structure 92 may include synthetic materials includingmetals, polymers, ceramics, hydrogels and/or other suitable materials. Apolymer reinforcing structure 92 may include resorbable and/ornon-resorbable polymers. Examples of resorbable polymers includepolylactic acid polymers, polyglycolic acid polymers, and/or othersuitable resorbable polymers. Examples of non-resorbable polymersinclude polyolefins, polyesters, polyimides, polyamides, polyacrylates,polyketones, and/or other suitable non-resorbable polymers. A metalreinforcing structure 92 may include titanium, tantalum, stainlesssteel, and/or other suitable metals and alloys thereof. For examplemetal fibers may be woven into a porous flexible reinforcing structure92.

The reinforcing structure 92 may be attached to the hard and/or softtissues of the proximal humerus PH by mechanical fasteners 94,adhesives, tissue in-growth, and/or other suitable attachment mechanism.The attachment mechanism may be permanent and/or bioabsorbable. Forexample, the reinforcing structure 92 may be screwed, pinned, sutured,or stapled to the bone and/or soft tissue adjacent the joint. Thereinforcing structure 92 may include preformed openings for receivingfasteners. The reinforcing structure 92 may include a reinforced edge tostrengthen the reinforcing structure 92 against pullout of fasteners.For example, the edge may be reinforced by hemming, molding, braiding,embedding a cord, and/or by other suitable reinforcement mechanism. Thereinforced edge may form a thicker portion of the reinforcing structure92.

FIG. 9 shows the interpositional implant 16 positioned within thearticular member 24 at the concave surface 60 of the proximal humerusPH. Referring again also to FIG. 1A, once the articular member 24 isfixed onto the proximal humerus PH or the stem 22 and the articularmember 18 is fixed onto the glenoid G, the interpositional implant 16 ispositioned between the articular member 24 and the articular member 18.In one embodiment, the interpositional implant 16 is a sphere or ballhaving a continuous convex surface 104. The interaction of the convexsurface 104 of the interpositional implant 16 with the concave articularsurface 32 of the articular member 24 and the concave surface 20 of thearticular member 18 allows articulation of the prosthesis 10. The sizeof the interpositional implant 16 is selected such that the convexsurface 104 of the interpositional implant 16 is engageable with boththe concave surface 20 of the articular member 18 and the concavearticular surface 32 of the articular member 24. In one embodiment, theinterpositional implant 16 is formed of a polymeric material, metal,ceramic, or a combination thereof. In one embodiment, theinterpositional implant 16 is coated with pyrolytic carbon such as thatdescribed in U.S. Pat. No. 6,436,146 (Hassler et al.) which is herebyincorporated by reference. Although FIG. 9 depicts the interpositionalimplant 16 as a sphere, the interpositional implant 16 may have anyshape having at least two convex surfaces, such as a disc. The disc mayarticulate directly with the glenoid G and the humerus H without theneed for articular member 18 of glenoid component 12 or articular member24 of humeral component 14. In another embodiment, the interpositionalimplant may be replaced by a glenosphere formed of pyrolytic carbon. Forexample, a convex surface of the glenosphere, or reversed glenoidprosthesis, may be adapted to articulate directly with the reversed,concave surface of the humerus H, and thus eliminate the need for aninterpositional implant.

As previously mentioned, the method of resecting natural bone andcompacting the resected surface of the natural bone with the resectedportion to form a concave articular surface for engagement with a convexarticular surface of an interpositional implant to repair or replace adamaged joint is not limited to repairing or replacing a damagedshoulder.

FIG. 10 shows a hand having a first interpositional implant 100implanted between metacarpal 102 and proximal phalange 104. The distalend 120 of the metacarpal 102 is resected and processed in a mannersimilar to the resection and processing of the glenoid and humeralcomponents 12 and 14 (shown in FIG. 1A) described above, to create aconcave articular surface 122. In the illustrated embodiment, theproximal end 124 of the proximal phalange 104 is also resected andprocessed to create a concave articular surface 126.

FIG. 10 also illustrates a second interpositional implant 106 implantedbetween metacarpal 108 and proximal phalange 110, and a thirdinterpositional implant 112 implanted between proximal phalange 114 andintermediate phalange 116. The bones 102, 104, 108, 110, 114 and 116adjacent the respective interpositional implants 100, 106 and 112 arepreferably resected and processed in a manner similar to the resectionand processing of the glenoid and humeral components 12 and 14 (shown inFIG. 1A) described above. In some embodiments, a natural concavearticular surface of one of the bones at the intersection, such as forexample on the proximal end 128 of the proximal phalange 110, may besufficient to retain the interpositional implant 106, making resectionunnecessary. The interpositional implants 100, 106 and 112 interact andfunction with the resected bones in a manner similar to theinterpositional implant 16 described above.

In another embodiment, the proximal end 130 of the proximal phalange 114is resected and processed as discussed herein. The naturally convexsurface 132 of the metacarpal 134 engages directly with the concavearticular surface 136, without the need for an interpositional implant.

As can be seen in FIG. 10, depending on the joint being repaired orreplaced, the shape of the interpositional implants 100, 106 and 112 maybe modified so that they are easily implantable between their respectivecomponents or bones. Although FIG. 10 depicts interpositional implantsbetween metacarpal bones and proximal phalanges and an interpositionalimplant between a proximal phalange and a middle phalange, aninterpositional implant may be positioned at any joint in the hand, forexample, between a middle phalange bone and a distal phalange bone orbetween the trapezium or scaphoid and a metacarpal bone.

FIG. 11 shows a foot having a first interpositional implant 200implanted between a metatarsal 202 and a proximal phalange 204 and asecond interpositional implant 206 implanted between the proximalphalange 204 and a distal phalange 208. The bones 202, 204 and 208adjacent the respective interpositional implants 200 and 206 areresected and processed in a manner similar to the resection andprocessing of the glenoid and humeral components 12 and 14 (shown inFIG. 1A) described above. Likewise, the interpositional implants 200 and206 interact and function with the resected bones in a manner similar tothe interpositional implant 16 described above.

Similar to the interpositional implants 100, 106 and 112 depicted inFIG. 10, the shape of the interpositional implants 200 and 206 may bemodified so that they correspond to the shape of the resected bonestructures within the foot. Although FIG. 11 depicts an interpositionalimplant between a metatarsal bone and a proximal phalange and aninterpositional implant between a proximal phalange and a middlephalange, an interpositional implant may be positioned at any joint inthe foot, for example, between a proximal phalange and a middle phalangeor between a middle phalange and a distal phalange. Any of thevariations disclosed herein can be used with the embodiments of FIGS. 10and 11, such as for example, the reinforcing structure or fasteners.

Various modifications and additions can be made to the exemplaryembodiments discussed without departing from the scope of the presentinvention. For example, while the embodiments described above refer toparticular features, the scope of this invention also includesembodiments having different combinations of features and embodimentsthat do not include all of the described features. Accordingly, thescope of the present invention is intended to embrace all suchalternatives, modifications, and variations as fall within the scope ofthe claims, together with all equivalents thereof.

1.-13. (canceled)
 14. A method of reinforcing a shoulder, the methodcomprising: forming a concave recess in an end portion of a humerus;disposing a reinforcing structure on the formed recess to form a concavearticular surface, the reinforcing structure comprising a first surfaceand a second surface opposite the first surface, the first surface beingpositioned between the second surface and the formed recess; attachingthe reinforcing structure to the cortical bone of the humerus; andsecuring a first implant having a convex articular surface to a glenoid.15. The method of claim 14, further comprising articulating the concavearticular surface of the reinforcing structure directly with the convexarticular surface of the first implant.
 16. The method of claim 14,further comprising positioning a convex surface of a second implantadjacent the concave articular surface, such that the reinforcingstructure is disposed between the humerus and the second implant. 17.The method of claim 14, further comprising selecting an implant formedof pyrolytic carbon.
 18. The method of claim 14, further comprisingselecting a reinforcing structure formed of material including at leastone of: a porous matrix, a scaffold, a reticulated bioceramic framework,a structured porous tantalum, a synthetic fiber mesh, and reinforcingfibers.
 19. The method of claim 14, further comprising selecting areinforcing structure comprising a resorbable polymer.
 20. The method ofclaim 19, wherein the resorbable polymer comprises at least one of:polylactic acid polymers and polyglycolic acid polymers.
 21. The methodof claim 14, further comprising selecting a reinforcing structurecomprising a non-resorbable polymer.
 22. The method of claim 21, whereinthe non-resorbable polymer comprises at least one of polyolefins,polyesters, polyimides, polyamides, polyacrylates, and polyketones. 23.The method of claim 14, further comprising selecting a reinforcingstructure comprising at least one of titanium, tantalum, and stainlesssteel.
 24. The method of claim 14, further comprising selecting areinforcing structure comprising a ceramic.
 25. The method of claim 14,further comprising selecting a reinforcing structure comprising ahydrogel.
 26. The method of claim 14, wherein attaching the reinforcingstructure to the cortical bone comprises the use of at least one of:sutures, mechanical fasteners, adhesive, and tissue in-growth.
 27. Amethod of reinforcing a bone, the method comprising: forming a concaverecess in an end portion of a first bone; disposing a flexiblereinforcing structure across at least a portion of the concave recess toform a concave articular surface, the flexible reinforcing structurebeing sufficiently flexible for the flexible reinforcing structure toconform to the concave recess of the first bone; attaching the flexiblereinforcing structure to the first bone; and securing an implant havinga convex articular surface to a second bone.
 28. The method of claim 27,further comprising articulating the concave articular surface of thereinforcing structure directly with the convex articular surface of theimplant.
 29. The method of claim 27, wherein the implant is a shoulderimplant.
 30. The method of claim 27, further comprising selecting aflexible reinforcing structure formed of material including at least oneof: a porous matrix, a scaffold, a reticulated bioceramic framework, astructured porous tantalum, a synthetic fiber mesh, and reinforcingfibers.
 31. The method of claim 27, wherein attaching the flexiblereinforcing structure to the first bone comprises the use of at leastone of: sutures, mechanical fasteners, adhesive, and tissue in-growth.32. A method of reinforcing a bone, the method comprising: forming aconcave recess in an end portion of a first bone; disposing areinforcing structure on the formed recess to form a concave articularsurface, the reinforcing structure comprising a first surface and asecond surface opposite the first surface, the first surface beingpositioned between the second surface and the formed recess; attachingthe reinforcing structure to the first bone; and securing an implanthaving a convex articular surface to a second bone.
 33. The method ofclaim 32, further comprising articulating the concave articular surfaceof the reinforcing structure directly with the convex articular surfaceof the implant.